32 percent of foods labeled 'gluten-free' contain gluten: study

A newly released study has reportedly found gluten in 32 percent of restaurant foods marked gluten-free.

The study, published in the American Journal of Gastroenterology, also found gluten in 53.2 percent of pizzas and 50.8 percent of pastas. Gluten can cause severe gastrointestinal issues for those with celiac disease and can even damage the small intestine.

"We all want people to be vigilant, but not too worried," Dr. Benjamin Lerner, who co-wrote the study, said, according to USA Today. "If you have celiac disease or it's harmful for you to ingest gluten, you should feel comfortable asking the waiter how things are prepared."

The researchers tested the foods using a portable device called a Nima that uses a small sample to detect gluten at levels lower than 20 parts per million.